Cell culture is a fundamental technique in life science or medical-related research. Traditional cell culture uses a simple container (such as Petri dish or multi-well microplate) as a vessel for cell culture, and this cell culture model mostly utilizes static culture and two-dimensional cell attachment culture. This type of cell culture has the following disadvantages:
(1) Due to manual replacement of the culture medium, a static cell culture may suffer the risk of microbial contamination. More importantly, such periodic medium replacement process could cause a relatively fluctuating environment, and under such improperly controlled conditions, the cellular response to the investigated conditions may become more complex.
(2) Cells cultured in the two-dimensional model, in which cells are cultured as a monolayer on a substrate surface, may have different cell physiology comparing with real (in vivo) physiological state, and under such culture conditions, the experimental results may lose authenticity.
Therefore, in order to provide a cell culture model which is stable, quantifiable and with physiological significance, the perfusion-type three-dimensional cell culture (e.g. cells are seeded within a polymeric scaffold, or in the form of multicellular spheroids) has been used in recent years. However, this kind of cell culture unit usually has complicated structure, high cost and large volume, which may not only limit the research throughput, but also consume relatively more experimental resources. More importantly, the cell culture conditions under conventional three-dimensional cell culture practices might not be regarded as homogenous mainly due to the chemical gradients that exist in these relatively large-scale three-dimensional cell culture constructs. Poorly-defined culture conditions caused by the chemical gradient phenomenon in a culture system may restrict the precise quantification of the link between cellular responses and investigated conditions. To tackle this technical hurdle, the miniaturization of perfusion-based three-dimensional cell culture is proposed.